1. Field of the Invention
The present invention relates to a copying machine for an electrophotography, and particularly relate to the improvement of the sealing structure for the photosensitive drum of the developing device and the cleaning device (hereinafter referred to as the developing device etc.) in the electrophotographic recording apparatus wherein the photosensitive drum is used.
2. Description of the Prior Art
In the conventional copying machine for an electrophotography, it has been tried that the side walls of the developing device etc. are kept close to the circumferential surface of the photosensitive drum as far as possible in order to prevent the developer to scatter out from the clearance where the side walls of the developing device etc. contact the circumferential surface of the photosensitive drum and when such arrangement does not prevent the scattering fully, sealing members made of elastic material such as foamed rubber or felt are arranged so that they contact the circumferential surface of the photosensitive drum to fill the clearance. With an arrangement of such sealing member, the scattering of the developer can be prevented but the photosensitive substance on the circumferential surface of the photosensitive drum to which the sealing member contacts tends to be scratched and the distance between the photosensitive drum and the developing device etc. becomes unstable when the sealing member is firmly compressed for the perfect sealing effect and especially in the part where the high stability is required such as the clearance between the developing sleeve and the photosensitive drum in the magnetic brush of the developing device, problems tend to happen. In order to prevent the photosensitive substance to be easily damaged, on the other hand, if the portions without the photosensitive substance and with a sufficient width are arranged on the both sides of the photosensitive drum, the photosensitive drum has to become larger by the size corresponding to such portions.